Model-based analysis of causes for habitat segregation in species (Crustacea, Isopoda).

On the shore of the rocky island of Helgoland (North Sea) two closely related isopod species, Pallas, 1772, and Rathke, 1843, share a similar fundamental niche but inhabit well-separated habitats. inhabits floating algae at the sea surface and accumulations of decaying algae on the seafloor, whereas primarily occurs in intertidal macroalgal belts. In laboratory experiments on individually reared isopods outperformed with regard to growth, reproduction, and mortality in both a fully inundated habitat and in a tidal habitat with 5 h of daily emergence.

Plasmid-mediated fitness advantage of Acinetobacter baylyi in sulfadiazine-polluted soil.

LowGC-type plasmids conferring resistance to sulfonamides have been frequently isolated from manure and manured soil. However, knowledge on the dynamics of plasmid-carrying populations in soil and their response to the presence of sulfonamides is scarce. Here, we investigated effects of the sulfonamide resistance conferring plasmid pHHV216 on the fitness of Acinetobacter baylyi BD413 in soil after application of manure with or without the sulfonamide antibiotic sulfadiazine (SDZ).

Modelling the effect of temperature on the range expansion of species by reaction-diffusion equations.

The spatial dynamics of range expansion is studied in dependence of temperature. The main elements population dynamics, competition and dispersal are combined in a coherent approach based on a system of coupled partial differential equations of the reaction-diffusion type. The nonlinear reaction terms comprise population dynamic models with temperature dependent reproduction rates subject to an Allee effect and mutual competition.

Process dominance analysis for fate modeling of flubendazole and fenbendazole in liquid manure and manured soil.

Fate monitoring data on anaerobic transformation of the benzimidazole anthelmintics flubendazole (FLU) and fenbendazole (FEN) in liquid pig manure and aerobic transformation and sorption in soil and manured soil under laboratory conditions were used for corresponding fate modeling. Processes considered were reversible and irreversible sequestration, mineralization, and metabolization, from which a set of up to 50 different models, both nested and concurrent, was assembled. Five selection criteria served for model selection after parameter fitting: the coefficient of determination, modeling efficiency, a likelihood ratio test, an information criterion, and a determinability measure.

From population-level effects to individual response: modelling temperature dependence in Gammarus pulex.

Population-level effects of global warming result from concurrent direct and indirect processes. They are typically described by physiologically structured population models (PSPMs). Therefore, inverse modelling offers a tool to identify parameters of individual physiological processes through population-level data analysis, e.